Call coverage arrangements provide redirection of an incoming call from an intended destination facility (e.g., a subscriber station) to an alternate facility where the call can be answered. One typical call coverage feature is the "send-all-calls" (SAC) feature. The SAC feature is normally activated for a subscriber station in response to a code dialed from the subscriber station or, if the subscriber station includes a SAC feature button, in response to pressing of the feature button. Following the activation of the SAC feature, all further calls destined for that station are diverted and redirected to an alternate call-answering facility. Subsequently, in response to either another code dialed from the subscriber station or a second pressing of the SAC feature button, the SAC feature is deactivated and calls destined for that station are once again directed to that station.
U.S. Pat. No. 4,682,354 discloses an improvement to the basic SAC feature that provides for the automatic activation of the feature. A failure to answer a call at a destination station for a predetermined number of rings results in redirection of the unanswered call and automatic activation of the SAC feature for all subsequent calls that are destined for this station, by the switching system that serves the destination station. Deactivation of the feature is accomplished manually, as before.